/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smack;

import org.jivesoftware.smack.filter.AndFilter;
import org.jivesoftware.smack.filter.PacketFilter;
import org.jivesoftware.smack.filter.PacketIDFilter;
import org.jivesoftware.smack.filter.PacketTypeFilter;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Registration;
import org.jivesoftware.smack.util.StringUtils;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Allows creation and management of accounts on an XMPP server.
 * 
 * @see Connection#getAccountManager()
 * @author Matt Tucker
 */
public class AccountManager {

	private Connection connection;
	private Registration info = null;

	/**
	 * Flag that indicates whether the server supports In-Band Registration.
	 * In-Band Registration may be advertised as a stream feature. If no stream
	 * feature was advertised from the server then try sending an IQ packet to
	 * discover if In-Band Registration is available.
	 */
	private boolean accountCreationSupported = false;

	/**
	 * Creates a new AccountManager instance.
	 * 
	 * @param connection
	 *            a connection to a XMPP server.
	 */
	public AccountManager(Connection connection) {
		this.connection = connection;
	}

	/**
	 * Sets whether the server supports In-Band Registration. In-Band
	 * Registration may be advertised as a stream feature. If no stream feature
	 * was advertised from the server then try sending an IQ packet to discover
	 * if In-Band Registration is available.
	 * 
	 * @param accountCreationSupported
	 *            true if the server supports In-Band Registration.
	 */
	void setSupportsAccountCreation(boolean accountCreationSupported) {
		this.accountCreationSupported = accountCreationSupported;
	}

	/**
	 * Returns true if the server supports creating new accounts. Many servers
	 * require that you not be currently authenticated when creating new
	 * accounts, so the safest behavior is to only create new accounts before
	 * having logged in to a server.
	 * 
	 * @return true if the server support creating new accounts.
	 */
	public boolean supportsAccountCreation() {
		// Check if we already know that the server supports creating new
		// accounts
		if (accountCreationSupported) {
			return true;
		}
		// No information is known yet (e.g. no stream feature was received from
		// the server
		// indicating that it supports creating new accounts) so send an IQ
		// packet as a way
		// to discover if this feature is supported
		try {
			if (info == null) {
				getRegistrationInfo();
				accountCreationSupported = info.getType() != IQ.Type.ERROR;
			}
			return accountCreationSupported;
		} catch (XMPPException xe) {
			return false;
		}
	}

	/**
	 * Returns an unmodifiable collection of the names of the required account
	 * attributes. All attributes must be set when creating new accounts. The
	 * standard set of possible attributes are as follows:
	 * <ul>
	 * <li>name -- the user's name.
	 * <li>first -- the user's first name.
	 * <li>last -- the user's last name.
	 * <li>email -- the user's email address.
	 * <li>city -- the user's city.
	 * <li>state -- the user's state.
	 * <li>zip -- the user's ZIP code.
	 * <li>phone -- the user's phone number.
	 * <li>url -- the user's website.
	 * <li>date -- the date the registration took place.
	 * <li>misc -- other miscellaneous information to associate with the
	 * account.
	 * <li>text -- textual information to associate with the account.
	 * <li>remove -- empty flag to remove account.
	 * </ul>
	 * <p>
	 * 
	 * Typically, servers require no attributes when creating new accounts, or
	 * just the user's email address.
	 * 
	 * @return the required account attributes.
	 */
	public Collection<String> getAccountAttributes() {
		try {
			if (info == null) {
				getRegistrationInfo();
			}
			Map<String, String> attributes = info.getAttributes();
			if (attributes != null) {
				return Collections.unmodifiableSet(attributes.keySet());
			}
		} catch (XMPPException xe) {
			xe.printStackTrace();
		}
		return Collections.emptySet();
	}

	/**
	 * Returns the value of a given account attribute or <tt>null</tt> if the
	 * account attribute wasn't found.
	 * 
	 * @param name
	 *            the name of the account attribute to return its value.
	 * @return the value of the account attribute or <tt>null</tt> if an account
	 *         attribute wasn't found for the requested name.
	 */
	public String getAccountAttribute(String name) {
		try {
			if (info == null) {
				getRegistrationInfo();
			}
			return info.getAttributes().get(name);
		} catch (XMPPException xe) {
			xe.printStackTrace();
		}
		return null;
	}

	/**
	 * Returns the instructions for creating a new account, or <tt>null</tt> if
	 * there are no instructions. If present, instructions should be displayed
	 * to the end-user that will complete the registration process.
	 * 
	 * @return the account creation instructions, or <tt>null</tt> if there are
	 *         none.
	 */
	public String getAccountInstructions() {
		try {
			if (info == null) {
				getRegistrationInfo();
			}
			return info.getInstructions();
		} catch (XMPPException xe) {
			return null;
		}
	}

	/**
	 * Creates a new account using the specified username and password. The
	 * server may require a number of extra account attributes such as an email
	 * address and phone number. In that case, Smack will attempt to
	 * automatically set all required attributes with blank values, which may or
	 * may not be accepted by the server. Therefore, it's recommended to check
	 * the required account attributes and to let the end-user populate them
	 * with real values instead.
	 * 
	 * @param username
	 *            the username.
	 * @param password
	 *            the password.
	 * @throws XMPPException
	 *             if an error occurs creating the account.
	 */
	public void createAccount(String username, String password)
			throws XMPPException {
		if (!supportsAccountCreation()) {
			throw new XMPPException("Server does not support account creation.");
		}
		// Create a map for all the required attributes, but give them blank
		// values.
		Map<String, String> attributes = new HashMap<String, String>();
		for (String attributeName : getAccountAttributes()) {
			attributes.put(attributeName, "");
		}
		createAccount(username, password, attributes);
	}

	/**
	 * Creates a new account using the specified username, password and account
	 * attributes. The attributes Map must contain only String name/value pairs
	 * and must also have values for all required attributes.
	 * 
	 * @param username
	 *            the username.
	 * @param password
	 *            the password.
	 * @param attributes
	 *            the account attributes.
	 * @throws XMPPException
	 *             if an error occurs creating the account.
	 * @see #getAccountAttributes()
	 */
	public void createAccount(String username, String password,
			Map<String, String> attributes) throws XMPPException {
		if (!supportsAccountCreation()) {
			throw new XMPPException("Server does not support account creation.");
		}
		Registration reg = new Registration();
		reg.setType(IQ.Type.SET);
		reg.setTo(connection.getServiceName());
		attributes.put("username", username);
		attributes.put("password", password);
		reg.setAttributes(attributes);
		PacketFilter filter = new AndFilter(new PacketIDFilter(
				reg.getPacketID()), new PacketTypeFilter(IQ.class));
		PacketCollector collector = connection.createPacketCollector(filter);
		connection.sendPacket(reg);
		IQ result = (IQ) collector.nextResult(SmackConfiguration
				.getPacketReplyTimeout());
		// Stop queuing results
		collector.cancel();
		if (result == null) {
			throw new XMPPException("No response from server.");
		} else if (result.getType() == IQ.Type.ERROR) {
			throw new XMPPException(result.getError());
		}
	}

	/**
	 * Changes the password of the currently logged-in account. This operation
	 * can only be performed after a successful login operation has been
	 * completed. Not all servers support changing passwords; an XMPPException
	 * will be thrown when that is the case.
	 * 
	 * @throws IllegalStateException
	 *             if not currently logged-in to the server.
	 * @throws XMPPException
	 *             if an error occurs when changing the password.
	 */
	public void changePassword(String newPassword) throws XMPPException {
		Registration reg = new Registration();
		reg.setType(IQ.Type.SET);
		reg.setTo(connection.getServiceName());
		Map<String, String> map = new HashMap<String, String>();
		map.put("username", StringUtils.parseName(connection.getUser()));
		map.put("password", newPassword);
		reg.setAttributes(map);
		PacketFilter filter = new AndFilter(new PacketIDFilter(
				reg.getPacketID()), new PacketTypeFilter(IQ.class));
		PacketCollector collector = connection.createPacketCollector(filter);
		connection.sendPacket(reg);
		IQ result = (IQ) collector.nextResult(SmackConfiguration
				.getPacketReplyTimeout());
		// Stop queuing results
		collector.cancel();
		if (result == null) {
			throw new XMPPException("No response from server.");
		} else if (result.getType() == IQ.Type.ERROR) {
			throw new XMPPException(result.getError());
		}
	}

	/**
	 * Deletes the currently logged-in account from the server. This operation
	 * can only be performed after a successful login operation has been
	 * completed. Not all servers support deleting accounts; an XMPPException
	 * will be thrown when that is the case.
	 * 
	 * @throws IllegalStateException
	 *             if not currently logged-in to the server.
	 * @throws XMPPException
	 *             if an error occurs when deleting the account.
	 */
	public void deleteAccount() throws XMPPException {
		if (!connection.isAuthenticated()) {
			throw new IllegalStateException(
					"Must be logged in to delete a account.");
		}
		Registration reg = new Registration();
		reg.setType(IQ.Type.SET);
		reg.setTo(connection.getServiceName());
		Map<String, String> attributes = new HashMap<String, String>();
		// To delete an account, we add a single attribute, "remove", that is
		// blank.
		attributes.put("remove", "");
		reg.setAttributes(attributes);
		PacketFilter filter = new AndFilter(new PacketIDFilter(
				reg.getPacketID()), new PacketTypeFilter(IQ.class));
		PacketCollector collector = connection.createPacketCollector(filter);
		connection.sendPacket(reg);
		IQ result = (IQ) collector.nextResult(SmackConfiguration
				.getPacketReplyTimeout());
		// Stop queuing results
		collector.cancel();
		if (result == null) {
			throw new XMPPException("No response from server.");
		} else if (result.getType() == IQ.Type.ERROR) {
			throw new XMPPException(result.getError());
		}
	}

	/**
	 * Gets the account registration info from the server.
	 * 
	 * @throws XMPPException
	 *             if an error occurs.
	 */
	private synchronized void getRegistrationInfo() throws XMPPException {
		Registration reg = new Registration();
		reg.setTo(connection.getServiceName());
		PacketFilter filter = new AndFilter(new PacketIDFilter(
				reg.getPacketID()), new PacketTypeFilter(IQ.class));
		PacketCollector collector = connection.createPacketCollector(filter);
		connection.sendPacket(reg);
		IQ result = (IQ) collector.nextResult(SmackConfiguration
				.getPacketReplyTimeout());
		// Stop queuing results
		collector.cancel();
		if (result == null) {
			throw new XMPPException("No response from server.");
		} else if (result.getType() == IQ.Type.ERROR) {
			throw new XMPPException(result.getError());
		} else {
			info = (Registration) result;
		}
	}
}